Nowadays, computers become essential electronic devices for making a presentation in a meeting. During the process of making a presentation, it is difficult for the lecturers to control the length of the presentation. Most lecturers may be unconscious that the presentation has been continued over a preset time period. As known, a lengthy presentation renders the meeting inefficient. For controlling the presentation on schedule, the lecturer need to frequently monitor the clock in the conference room or the watch worn on his hand. Otherwise, the lecturer should be alerted by someone during the presentation.
For controlling presentation, a presentation controlling device is disclosed in US Patent Application No. 20050248528, entitled “Time management in presentation device”. The presentation controlling device includes a timer module, a display module, a timer button and an alert module. By activating the timer button, the user may set the preset presentation time interval into the presentation controlling device. When the timer button is pressed for each time, a preset presentation time interval between a current time and an end time is increased by a preset time increment, e.g. 15 minutes. For example, if the user presses the timer button once, the preset presentation time interval is 15 minutes. If the user presses the timer button twice, the preset presentation time interval is 30 minutes. The information associated with the preset presentation time interval is shown on the display module. After the presentation starts, the display module shows a countdown of the time interval from the initial time to the end time to show the remaining presentation time. In addition, when the remaining presentation time has reached a certain level, the alert module may alert the user.
Although the presentation controlling device may alert the user of the remaining presentation time, there are still some drawbacks. For example, as previously described, the preset presentation time interval is set by activating the timer button. Since the preset presentation time interval is increased by a preset time increment when the timer button is pressed for each time, this process is troublesome. In a case that the preset time increment is 15 minutes, the preset presentation time interval should be equal to a multiple of 15 minutes, e.g. 15, 30, 45 minutes, and so on. Generally, the preset presentation time interval may be less than 15 minutes (e.g. 5 or 10 minutes) or much greater than 15 minutes. For example, if the preset presentation time interval is 150 minutes, the user should continuously press the timer button for several times. Therefore, the conventional presentation controlling device is not suitable for making a presentation requiring a very large preset presentation time interval.